Light boxes having mirrors for forming a plurality of images have been known and used in the past. Disclosures on this general subject matter are found in U.S. Pat. Nos. 2,203,244 and 2,221,889. Both of these patents teach the use of motors for rocking a first of a pair of mirrors relative to the other mirror about a horizontal axis through the first mirror to generate light images which appear to move at all times during operation of the motors.
In U.S. Pat. No. 2,203,244, a light box is described with a front transparent mirror and a rear opaque mirror, the mirrors having opposed reflecting surfaces, and a complex motor-lever assembly for causing the opposed mirror surfaces to assume different angular positions by continuously moving one of said mirrors relative to the other mirror by way of the motor.
U.S. Pat. No. 2,221,889 uses the same type of complex mirror arrangement and motor drive means for continuously moving one of the mirrors relative to the other mirror. U.S. Pat. No. 2,221,889 improves on the structure of the first patent wherein disappearing indicia are combined with constantly visible indicia. This is accomplished by having part of the reflecting surfaces of the mirrors opaque for the purpose of carrying out a pattern or scheme of any desired arrangement of character or appearance of the indicia.
Another disclosure in the light box field having reflecting surfaces includes U.S. Pat. No. 3,790,772 wherein a light box has mirrored inner wall surfaces with multiple light sources in a light box. Interchangeable exterior wall panels are also carried by the box. The wall panels do not provide for angular arrangement of the mirrored surfaces; thus, the light box of this patent is limited in use as to the light image designs that can be formed with the light box.
By virtue of the limitations and complexity of the prior art structures as exemplified by the above patents, a need exists for improvements in light boxes which simplify the way in which the mirrors are held in operative positions with respect to each other without detracting from the aesthetic designs which can be formed by images of the designs. The present invention satisfies this need.